Extension ladder and lock therefor



Oct. 28, 1952 R. o. BALOGH EIAL 2, 5,

EXTENSION LADDER AND LOCK THEREFOR 3 Sheets-Sheet 1 Filed Nov. 8, 1949 I E 11? HIM 5% 1 my 5 F4 Oct. 28, 1952 R. o. BALOGH ETAL 2,615,609

EXTENSION LADDER AND LOCK THEREFOR Filed Nov. 8, 1949 3 Sheets-Sheet 2 Oct. 28, 1952 R. o. BALOGH ETAL 2,615,609

EXTENSION LADDER AND LOCK THEREFOR Filed Nov. 8, 1949 I5 Sheets-Sheet 3 lllllln NVENTORS BY 5066M! 63 flan/w.

Aim/"new for 0. A106 Patented Oct. 28, 1952 land, Ohio, assignors, by mesne assignments, to McCabe-Powers Auto Body 00., St. Louis,

Mo., a corporation of Missouri 8 Application November 8, 1949, Serial No. 126,179

6 Claims.

This invention relates to an extension ladder carried by a vehicle and adapted to lie in approximately horizontal position during travel of the vehicle. and be raised at an angle for use.

With an extension ladder so carried there is a To tip the ladders as a unit on the pivot 15, we tendency of the extension portion to shoot forprovide a piston and cylinder construction adaptward on the supporting portion by momentum ed to be actuated by fluid pressure. We have whenever the vehicle suddenly stops. Our inshown a cylinder 40 pivoted at 4| to a bracket-42 vention is directed to automatic means for lockon the sleeve I2 and a piston having axially exing the extension and preventing such displaceten rod 45 eenneeted t the main ladder y ment when the ladder is horizontal while allowrigid brace b s 46 and Suiteble fluid pressure ing free movement of the extension portion when acting on the piston at the lower end of the rod the ladder is tipped up for use. 45 serves'to tip the combined ladders upwardly Means by which we accomplish this automatic into ous positions, indicated in Fige- 5 locking of the extension portion of the ladder is and 6. V r v illustrated in a preferred form in the drawings To b e ready access to t e ladde s the e is hereof and hereinafter more fully described and p o a p ladder S OWn as pivoted by a its essential novel features are summarized in the cross r 5 to rearwardlv x n in p r n claims. of the main ladder. The lower portion of this In the drawings, Fig. l is a side elevation, p a der r s S i y st a b acket 52 partly broken away, of a highway truck equipped carried by the sleeve l2. As the ladders 20 and with an extension ladder pivotally mounted on 30 are tipped p, the p ladder 50 Slides downthe pedestal carried by the truck; Fig. 2 is a plan Wardly across the Supporting bracket ya$ i of a portion of the extension ladder over the dice/fled by the broken lines in 1 nd as shown pedestal in the region indicated by the line 2-2 in on Fig. 1; Fig. 3 is a rear elevati n f th same To look the extension ladder in place on the portion in the region indicated by the line 3 s main ladder when the ladders are horizontal, on Fig. 1; Fig. 4 is a side levati on larger we provide a lever latch 60 pivoted on the pivot scale of th pedestal n adjacent portion f rod .5l andextending forwardly beneath the endthe ladder disclosing our latch in operative posi- 30 most rung 3| 0f t e extension ladder in its untion to lock the extension ladder; Fig. 5 is a side extended Position This latch has an upwardly elevation partly broken away of the same parts extending l at its free end adapted to oo t theledder tipped upwardly; Fig. 6 is a View around such rearmost rung 31. A pin 6| on the of the pedestal and ladder with the ladder raised step ladder beneath the latch limits its downt t maximum ward movement and a tension spring 62 tends to As shown in Fig 1, A indicates any suitable maintain thelatch in engagement with the stop vehicle, for instance, a highway truck. [0 desigpm as shown In Flgs- 4 and 5 nates a vertical post comprising the stationary It W111 be seen from 4 that When the portion of the ladder-supporting pedestal, mounttiers are .hpnzontal.the latch is definitely retained ed on the truck this post having a Spreading in a position hooking around the rearmost rung base H by which it is rigidly held in the upright of the extension ladder and effectively locking position- Embracing the post lo so as to be it to the main ladder. When, however, the ladrotatively mounted thereon is a vertical sleeve ders swung P the operation of l2 which has a rectangular head [3. Two side the .plston cytmder mechanism as indicated rails 20 of the main ladder extend onto opposite 5 for 1ns,tance m Flg? Such movement frees the sides of this head and are pivotally secured to it extehslon ladder from the latch, t the X-' by a transverse Shaft The rungs 2| of the tension ladder may be elevated along the main main ladder extend from one of the rails 20 to laddert other in the usual manner When the ladders are raised the maximum The extension ladder has side rails 30 which 50 amount as shown in 6, this may bring the may rest on t rungs 2 f t main ladder and latch against the head I 3 of the carrying sleeve. carry their own rungs 3!. Suitable means, not If S0, the latch Simply Swings p y 0 its shown, may be provided to slidably hold the exp t, Stretching the Spring as, shown in this tension ladder on the main ladder, as well as fi v means to propel the extension ladder along the '55 It will be seen from the description given that 2 main ladder to extend the same as desired. A hand wheel I! rotatably carried'by the sleeve head [3 may operate suitable mechanism (not shown) to'swin'g the ladders laterally as a unit.

we have provided a very simple automatic lock for preventing shifting of an extension ladder during its transportation. As soon as the ladder is tipped for use, the lock is automatically released from the extension so that the latter may be shoved lengthwise of the supporting ladder in the usual manner. When the operator is through using the ladder in its extended position the ordinary operation is to lower the extension to its initial position and thereafter tip the combined ladder downwardly into horizontal position. At the conclusion of such tipping movement the latch again becomes effective to automatically lock the extension ladder, so that it cannot be jarred or forced by momentum or gravity out of position on the main ladder.

We claim:

1. The combination of a supported standard, a main ladder pivoted thereto on a horizontal pivot, an extension ladder slidable lengthwise on the main ladder for disposition optionally in extended and retracted positions relative to the main ladder, a latch carried by the main ladder and adapted to engage the extension ladder or be free therefrom, a depending step ladder pivotally carried by the main ladder, and a stop on the step ladder adapted to hold the latch in engagement with the extension when the extension ladder and main ladder are substantially horizontal and the extension ladder is in retracted position.

2. The combination of a substantially vertical support, a main ladder pivoted thereto for optional movement from a substantially horizontal position to an angularly disposed upright position, said main ladder when in horizontal position extending forwardly from the support and having a terminal portion extending rearwardly from the support, an extension ladder slidable lengthwise on the main ladder for disposition optionally in extended and retracted positions relative to the main ladder, a step ladder pivoted to the terminal portion of the main ladder and extending downwardly therefrom at the rear of the support, whereby the step ladder is lowered vertically when the main ladder is pivoted upwardly on the support, a latch pivotally mounted on and extending forwardly from the pivot of the step ladder, said latch having a detent-element positioned for engagement with the extension ladder when the extension ladder and main ladder are substantially horizontal and the extension ladder is in retracted position to hold the extension ladder against unauthorized forward movement, and a stop on the stepladder for engaging and holding the latch in such position when the main and extension ladders are horizontal.

3. The combination of a substantially vertical support, a main ladder pivoted thereto for optional movement from a substantiall horizontal position to an angularly disposed upright position, said main ladder when in horizontal position extending forwardly from the support and having a. terminal portion extending rearwardly from the support, an extension ladder slidable lengthwise on the main ladder for disposition optionally in extended and retracted positions relative to the main ladder, a downwardly extending step ladder pivoted to the terminal portion of themain ladder and extending downwardly therefrom at the rear of the support, a latch carried by and extending forwardly from the step ladder, said latch having, a detent-element positioned for engagement with the extension ladder when the extension ladder and main ladder are substantially horizontal and the extension ladder is in retracted position to hold the extension ladder against unauthorized forward movement when the main and extension ladders are horizontal, and means for holding the latch and stepladder together for simultaneously swinging movement downwardly and away from the main ladder as the latter is pivoted upwardly on the support thereby disengaging the detent-element from the extension ladder to permit said extension ladder to be extended upwardly and forwardly in relation to the main ladder.

4. The combination of a substantially vertical support, a main ladder pivoted to the support for optional movement from a substantially horizontal position to an angularly disposed upright position, said main ladder when in horizontal position extending forwardly from the support and having a terminal portion extending rearwardly from the support, an extension ladder mounted on the'rnain ladder and slidable lengthwise of the main ladder for optional disposition in extended and retracted positions relative to the main ladder and having a plurality of spaced parallel run s, a depending step ladder pivotally mounted on the terminal portion of the main ladder, bracket means extending rearwardly from the support and slidably engaging the step ladder for holding the step ladder in depending position as it shifts downwardly responsive to upward tilting movement of the forward end of the main ladder, a latch carried by and extending forwardly from the step ladder and having an upwardly extending hook adapted to engage one of the rungs of the extension ladder when the extension and main ladders are horizontal and the extension ladder is inretracted position, a stop mounted on the step ladder and positioned for normally engaging the underside of the latch, a spring normally biasing the latch downwardly against the stop, the stop being positioned to hold the latch in said rung-engaging position whereby the latch hook is caused to release the extension ladder responsive to lowering of the step ladder and the stop when the main and extension ladders are tipped, said spring furthermore allowing the latch to swing relatively upwardly if it comes into engagement with the support after being released from the extension ladder.

5. The combination of a support, a main ladder pivoted thereto a comparatively short distance in front of its rear end, an extension ladder slidably mounted on the main ladder for disposition optionally in extended and retracted positions relative to the main ladder, a latch pivoted to the main ladder at the rear of the pivot of the main ladder and engaging the extension ladder to lock the ladders together in one direction when they are substantially horizontal and the extension ladder is in retracted position, and means for retaining the latch extending-in an approximately fixed direction as its pivot is lowered by the upward tipping of the ladders, whereby such an upward tipping frees the extension ladder from the latch.

6. The combination of a support, a main ladder pivoted thereto a relatively short distance in front of its rear end, an extension ladder slidably mounted on the main ladder for disposition optionally in extended and retracted positions relative to the niainladder, a latch pivotally carried b the main-ladder and extending forwardly and having an upwardly extending jaw adapted to engage the extension ladder when the ladders are substantially horizontal and the extension 5 ladder is in retracted position, a, depending member pivotally carried by the main ladder, bracket means extending from the support and slidably engaging the depending member for guiding thelatter to move in an approximately constant upand-down direction as the main and extension ladders are tipped, a stop on said depending memher, and a spring normally maintaining the latch in engagement with the stop to hold the latch extended in a substantially constant direction as its pivot is lowered by the upward tipping of the ladders.

ROY O. BALOGH.

EUGENE G. HUMPAL.

6 REFERENCES CITED The following references are of record in the v file of this patent:

UNITED STATES PATENTS Number Name v Date 2,026,535 Hooker Jan. '7, 1936 2,116,470 Kiley et a1 May 3, 1938 2,222,616 Hawkins Nov. 26, 1940 10 2,238,665 Troche Apr. 15, 1941 

